Abstract 1845: Automated Assessment of Left Atrial Function from Time-Left Atrial Volume Curve by Velocity Vector Imaging
Background: Velocity vector imaging (VVI) is one such approach that allows measurement of myocardial velocity and deformation in the apical and short-axis views of a cardiac chamber. Using VVI, time-left atrial volume (LAV) curve can be automatically provided. Thus, we evaluated whether VVI can be used for the measurement of LA function analyzed with time-LAV curve by comparison with conventional manual tracing method in echocardiographic images.
Methods: In 30 subjects (10 normal subjects and 20 cardiac patients), the four-chamber images were obtained with 2D echocardiographic system (Siemens, Sequoia). LA endocardial border was traced at end-diastole and tracked automatically during one cardiac cycle in VVI method. Finally, time-LAV curve was automatically provided. The minimal, maximal LA volume (LAVmin, LAVmax), reservoir volume (LAVR) and booster pump volume (LAVB) were measured from LAV curve. Using the disk summation method, the same parameters were measured by the manual tracing on every frame during one cardiac cycle. We compared the results with ones by the manual method.
Results: There was an excellent agreement between VVI and the manual method in the LAVmin, LAVmax, LAVR and LAVB(r=0.98, r=0.98, r=0.88, and r=0.80 respectively). The mean difference of LAVmin, LAVmax, LAVR and LAVB between VVI and manual methods were −1.2±3.8ml, −0.5±4.3ml, 0.2±4.4ml, and 1.3±3.3ml respectively. The time for requiring LAV curve was significantly shorter in VVI (64±22 seconds) compared with the manual method (22±4 minutes).
Conclusion: Time-LAV curve from VVI can thus be utilized for noninvasive, automated quantitation of LA function in 2D echocardiography within a short time.